Jury selection began today in the trial of Kerry Kennedy, daughter of Robert Kennedy, charged with driving while impaired. Tests showed she had a sleeping medication in her system alt the time of the accident and the trial begins as a new report says the number of Americans turning to sleeping pills is skyrocketing. ABC's linsey Davis now. Reporter: They're already among America's popular P prescriptip prescription drugs. New report saying the use of the most common brands has tripled in just over a decade. The new research suggests more than 9 million Americans are now popping a pill at night to get some Zs. Who? Primarily women and those 70 and older. In fact, women suffer from sleeplessness twice as often as men and menopause is often cited as the reason. Concern about the possibility of misuse and side effects. For women, it can be an issue because they might be taking too much of a prescribed dose. For an elderly, it can be an issue because they tend to be more sensitive to medication. Reporter: Take ambien for example the most widely prescribed sleeping pill, of the prescriptions in 2011, 63% were for female. Women account for 274% increase in ambien emergency room visits. Mixing ambien with alcohol or other drugs. The fda recently recommended lower doses for Americans after finding out they're more susceptible to next morning impairment. Kerry Kennedy, the 54-year-old daughter of Robert Kennedy, says she was sleep-driving the morning of her crash back in July 2012. She said she doesn't remember anything. Linsey Davis, ABC news, new York.

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Kerry Kennedy Driving on Ambien

Daughter of RFK will be facing justice in a drugged-driving trial.

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